Automatic telephone-exchange system.



G. DBAKIN.

AUTOMATIC TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED FEB. 2, mm.

1,024, 184, Patented Apr. 23, 1912.

4 BHEIITB-SHEET 1.

AUTUMA'NG THLRIFHQ APILIUMEEOY 1,024, 18%,

G. DEAKIN. AUTOMATIC TELEPHONE EXCHANGE SYSTEM.

APPLIUATION FILED FEB. 2, 15111,

Patented Apr. 23, 1912.

4 SHEETS-SHEET 3.

G, DEAKIN, AUTOMATIC Tm mmqn EXCHANGE SYSTEM AIEI-TUATION FILED $33.2 1911 1,024,184. Patented Apr. 23, 1912 4 SHEETS'SHEET 4 vwwmssmsv WM/ 3M4; MAQJLM4QN.

the second group to the figure and so on to the tenth group which corresponds to the figure 0. binve the connector must select the last two digits of every number it follows that each connector must have access to at least one hundred lines, '1'. (1., 00, O1 to 98, 99. In my ini u'ovcd party line system ar 'anged for example. for the purpose of illustration, for four stzuions on a line, there would be four classes of connectors, each class having :iiit'tFi? to the same group of lines. This would be am-oinplirhcil by multiplying the connector bank contacts. they being numbered from ()0, U1 to US, 99, before each class of connector. Now to permit the selection of the proper connector. it is only necessary to connect ea h class of connector to dillcrcut groups of bank contacts or levels on the preceding selectors. Thus, in the particular case of the four party lines cited, the first class of connectors might be connected to the first group of trunk conta ts. on the selcc' tors, and the. second, class of connectors to the Second group of contact s, and so on. In this manner, line (It, for example would be selected whenever the following last three digits were called, ltll, 201, 301, 401, provid ing. of course, that any previous digits called are the same in all cases. In each case, however, a difl'crcnt. reep of connectors would be selected with a result that. the corresponding station only, on the party line, would be called.

In Figure 1 is shown a diagrammatic circuit sketch of a simple form of an automatic telephone set. In Fig. 2 is shown a circuit sketcli of a sclectorfor extending a call from the subscribers line to a connector or to another selector. In Fig. 3 is shown a circuit sketch of my improved form of party line connector. Fig. 3 shows a modi titration of the ringing circuit of the connector circuit. shown in Fig. 3. In Fig. 4 is shown the line circuit condition with respect to the connector during the establishment. of a reverting call. Figs. 5 5 and 5 illustrate the line circuit conditionswith pect to the connector met. with in attempting to establish a connection with a busy line. In Fig. 3 is diagrammatieally shown the ringer and ringing generator connections of a two-party line syJtem, adapted for use with automatic apparatus. In Fig. 7 is diagrammatic-ally shown the ringer and generator connections of a Four or other multiparty line system, employing harmonic or other similar ringers requiring a different kind or arrangement of ringing generator current.

In the accompanying drawings, Fig. 1. is a simplified sketch of the general form of subscrihers tclepiioiw circuit, required to operate the automatic central oillce apparatus, referred to hereinafter. It forms no part of my invention and is shown here,

merely with the purpose of illustrating the operation of the selector and connector described later on. A detailed description of the full circuit. will be found in U. S. Patent No. S!5l'3,(339, granted to Edward D. l ales 'on He number 24 1907. In the li urc conl r a a tact springs 70, 71 and 72 illustrate parts of both the calling and release circuits, but in reality. separate sets of springs are used. The calling circuit springs are controlled by the dial on the face of the subscribers set, whim llltll atlhrds the subscriber the necessary means for sending the proper impulses over the line to the central office apparatus. The release circuit springs are controlled by he switch hook. Contact springs 73 and 74 are controlled by the calling dial and break contact when the dial is moved out. of its normal position. The object of these springs is to open the normally closed circuit through the telephone set while calling. A ringing hey is shown at 96. \Vhcn operated, it opens the telephone circuit through contact. springs 75 and 76 and connects line Vii to arth 1.3, at 77.' A transmitter is shown at 78; an induction coil at. 81', a switch hook and Contact at T9 and and a receiver at 82.

Fig. .3 illustrates a selector of the general type, described in U. S. Patent No. 815,321, granted to Messrs. Alexander E. Keith, John Erickson and Charles J. Erickson on March 13, 1906. This selector forms no part of my invention and is referred to herein for the purposeof illustrating the preferred form of my improved connector circuit and party line system. V and R are line relays, controlling springs 1', 2'. i 4 and 5. PM is a magnet, commonly known as the private magnet, controlling side switches 88, 89, 9t). 91 and 92. M is a release magnet; HR :1 release relay; VM is a magnet controlling the vertical movement 01 the wipers, RM is a magnet controlling the horizontal movement of the wipers. These magnets are commonly known as the vertical and rotary i'nagncts respectively. Vll, Pl and RW represent the vertical. private and rotary wipers respectively. RB represent the vertical, private and rota y selector bank contacts, which also form part of the connector circuit shown in Fif 3. L and RL represent the line wires from the subscribers station VN, PK and RN represent the vertical, private and rotary connector bank contacts also shown in Fig.

CU is a cut oil relay.

Figs. 3 and 5 illustrate my improved connector circuit. VB, RB and PB represent the vertical, rotary and rivate selector bank contacts respectively, a so shown in Fig. 2. V and R are line relays, controlling springs 1, E2, 3, 4 and 5. A is relay bridged across the calling line side of the connector and B a similar relay bridged across called line VB, PB and the three swinging springs 51, 5t and 56;

l l l 10, ll. l2 and 13 represent. side swim-hos controlled by the private manor-t PM: Yi f, PW- and RW rrprosrnt tho vortiral, private and rotary 'wiprrs rusportivuly. and are urrangvd to rngiagro ronnu-tor bani: contort VN, PN and RN. Tho ronnortor bunk wontarts are i-onnrctml to tho line sitlr of tho srlertor rirruit as shown by rot-responding lottt-rs in Fig. .2. Springs 58 and Gil represent rontnrts r'ontrollrd by tho uonnei'tor shaft. These contacts clos wherunrr a shaft is out of its normal position; l6 and i7 represt-nt rondrnsors through whit-h ('on versation is rarried on; 47 rrprrsonts a nondenser plared in tho grounded sitlv of ring ing circuit; (l6 represvnts a husy tono trans-- former or its equivalent.

'l lur side switrh of both tho sulrrtor and connector Consists of a iunuhor of nimiziblc springs and fixed contarts. and is ronliolltd by the private mag-not, tho whole being so designod that tho side switrh is normally hold in what is called its first or niirlual position under the tension of a spring or springs, whioh tend to fort-o tho side switrh into its so t-alled second and third positions. The priwito inagnot of the runner-tors whern first Pnt-rgized and then dei nergim-tl, opurairs an oscapeu'lent, causing the shit switrh to step from its first or normal position into its second position. This moans that tho movable springs are caused to break con nection with the first series of fixed routzu'ts and make mnnortion with tho surond serits of fixed contarts. Vhun the private iii-agnet is energized and det norgized a t-LClllltl time, it r'auses the side switth to stop from its second to its third or last position. Tho side switch of a selector steps into its so:- ond position when energized and into its third position when drtnrrgim-tl. The s'nlv switch is caused to resunuits normal posi tion by energizing the release magnet. \Vllit'l) magnet in addition to forcing tho side switch back into its normal position, re leases tho switc-h shaft to which the wipen are nttarhed, allowing the shaft, first to rolate horizontally, and then drop rerti 'ally to its normal position, the shaft. as before stated, being capable of a vertical. and horizontal motion.

in both the selector and ronneotor. line relays V and V and R and R operate in the following manner: hen, relay of the tion of the ronnector V is (11t1 i)?(l, -oi'iturt is made hetwron springs 23 and l. When relay R is energizod ('ontnvi i uunlo brtwvt-n s n'ings t and 5. Whrn rvlnys V and ll are. onergiaotl Fillllllltlllt'f ll i t'ontai-l is tuzulo bolWlftfll springs l uiul in addition to tho rontut-ts pruriouslt nmntionod.

in Figs. l, Ti, H and T are illustrutrd lino rirvuit i-ondili n inroli'rd in illl. improved purl lino systvni. ln Fig. l is iliugi'unr ninth-all illu-trut ll tho rolling lino virruiti rondition (bu-in; :1 rvvrrtingg' ull when the side switch of lho t'tmntu-tm is in its set-0nd position. In l igs. 5" and 5 are illustrntcd diagn'anunutirullr. iilli tilttlli' condi tions of ronnortor bunk ('ontuots of busy linos, surh us :llt with in urinal prai'tirr.

Fig. 71. row-wont: tho illlt t'irruit rondi" tion of railing lin lwforo tho 'allud subl'l'iilil' llttv illl\'\\'i'l(l. in Fig. 51 shown the circuit condition of tho sumo lint after tho sulIH-ribrr has fHl!-\-'tl'ttl. in Fig. 5 is shown the lino circuit t'lliltillllli] of a ('zillrd lino doring,tonu-rsntion. in Fig. 6 is illus' tutr-d eflizrgrununatirnlly, the subscribers station ringrr and ventral ollirr ringing gonerator (tiliIKtliOIlS in my improved tww party lino srstvni, matting ow of the ordi nary main line oquipnwnt. A and ll represent the two stations. At station A, ringer Q. connected to ground 15, from line wire Rli through r-onllonsvr I. At station l3, tho liIlfItl Q. is lllltlfli l zu-ross line in series with ooi'ulrnscr 1": tilt and 96 represent ringing troy t-ontiuxts: (l roprvsouts the arangouwnt of tho ringing rirvuit of :1 Porn Httfltlt on a rt-gulur oomn-C'tion when station A only is to ho (rulhul. At l) ltIlTCSQl'llt'tl tho zn'rungvmrnt of tho ringin; virvuit of a ('Ullllttlifll on a regular ronnrt-tion when sta' tion it only is to ho ralli-d. At l l is 'rrpre sentod the ringing tfil'tTllll arrangement of thrt-onnt-rtor on a rrrt-rting (:lll, when station A is railing! station l5 m when station l, is rolling: stution A. It should be notod that when station A rails station 13 the ground required to oporato ringer Q, is supplied by ringing lrvy tltl of station A. in Fig. 7 is lliugrunnuati ally illustrated a font-party lino systi-in, employing harmonic. or other spvcial ringers, ringer It, being so ilvsigrnrd us to operutv only on current from ringing gt-nu'rutor 1 it on t'urrent from ringing grnerator F, and so on. K. K etc. represent ringing keys.

To establish a t-onnvction with the profurroil form of in improved arrangt-nu-nt of equipment and circuits. the calling sulr srrihrr removes rot-river, 82. Fig. 1, from switch hook 80. thereby (losing the lil circult to the central othce through contai'ts 7t) and R0. Tho subscriber may now proreod ti) opuruto the calling dial as drt'orinined by the nuniorr of the station to ho nullod, Ono zu1- culling dial is to cause tho grounded spring 70, to make a series of contacts with spring 71, the number of contacts corresponding to the digit called. At. the end of theseseries of contacts and just be- 'fore the dial resumes its normal position, a momentary impulse is sentover the opposite side of the line by a momwltary connection made between ground spring and spring 72. The closing of contacts T0 and 71 'auses current to flow from ground 15, Fig. 1., through 70, 71, Ta. Til, line wire VL, to the central otiiec. thence through H and 8;, Fig. :2, 8Q, 88, winding of relay V, to battery it. and thence to ground 13. The current thus caused to flow energizes relay V, Fig. 2, causing contact to be made between springs 3, and 4, with a result that a closed circuit is established from ground 15, Fig, 2 through 4', 3, 94. winding of vertical magnet, Vl\*[.hattery1t,to ground 15. The energizing of the vertical magnet, VM, causes the selector shaft to step up one level, placing the vertical private and rotary Wipers, Viv, 1" and HIV, respectively opposite the first level or horizontal row of selector bank contacts. VB, PB and RB. By sending a series of impulses over line wire V L. as above described, the vertical magnet VM', causes the selector shaft. to step up one level for each impulse. As previously stated the final impulse sent over line wire V11, is followed by a similar one over line wire Bl A circuit being establislned from ground, 15. Fig. 1, through 70, 72, line wire ltli. to central office, thence through St), 87, Fig. '2, 90, 90. winding of relay 1". to battery M, and thence to ground 15. llelay ll now. operates and closes contact between springs l. and 5', Fig. 2. with the result that a circuit is established from earth 13. Fig. through t, 5, winding of private magnet PM, battery l4, to earth 15. This causes the private nuignet PM, to operate and open c ntact at M and step, so to speak. the five side switches. 98, 89, 90, 91 and 9'3 into their second position, thus connecting switch S8 to c ntact 88, 89. to 85), 90, to 90. E i to JP. and J9 to 92. The closing of contact between )1 and 91. causes a rurrent to llow from ground 15, through switch i l, 91, winding of rotary magnet HM. through vibrating contact 95, battery 1-4. to earth again at 15. The rotary magnet, RM. thus energized, causes the selector wipers to be rotated into connection with the first set of tl'llllh' con tacts of the level to which they have been stepped. Should the first trunk be busy, :1 ground connection will he found upon the private bank contact Pl). A current will now flow from PB to TVv, through winding of relay RR, 89, 89, winding of magnot PM, battery Lit, thence to ground T5. In this manner, the private magnet, PM, will remain energized and the rotary magnet will continue to cause the switch shaft and wipers to rotate. It should be stated that the winding of relay RR, is of a comparatively low resistance compared with the winding of magnet PM. For this reason, relay RR, is not energized when a circuit; is established from the ground on the private bank contact PB, through the wind ings of relay RR, and private magnet, PM, to battery 1%. hen a non-busy trunk is picked up, the ground connection on PB will not be found. The circuit thus opened allowsthe private magnet PM, to resume its normal position and in so doing causes the live side switches to assume their third position, connecting S8 to 88 89 to 89 90 to 9O, 91 to 91 and 92 to 92 The stepping of side switch 91 from its second position where it made contact with 91 to its third PtlSlllOI] making contact with 91, opens the circuit through the rotary magnet RM, thereby causing the further rotation of switch shaft to cease. The stepping of side switch 89 into its third position placed a ground on the private wiper through the low resistance winding of relay RR. In this manner the selector bank contacts picked up are made busy to all other selectors; The stepping of side switches 88 and 90 into their third position, removes line relays V and R from connection with the line wires VL and RL respectively, and in place thereof, connects the line wires VL and Rh to the vertical and rotary wipers vw' and lilV". respectively. To make the calling line busy to any other calling line, side switch 99, in its second and third positions. places a ground on the private contact P PN, in the connector banks. Thus, should a coimeetor attempt to select the calling line, the latter will he found busy andthe vtormcr will fail to make connection, as described later on. The selector as above described is now in position to permit the next series of impulses to be passed on to the next selector or to a connector as the case may be.

In large exchanges, requiring the use of five digits in each number, first, second and third selectors are used to select the first three digits. after which the call is completed by a connector, and in my improved system under consideration, as follows: The subscriher in calling the first of the last two digits of the desired number, causes a series of impulses to he sent out over line wire VL, as previously described, a circuit being established during each impulse, from earth 15, Fig. 1, through 70, 71, 75, 76 Fig. 1, line wire VL. and 8% Fig. 2, 88. 88, wiper VVV", bank contact VB Figs. .2 and 3, winding of relay V. Fig. 3. winding 63 of relay A, hat tery 14 to earth 15. 7 causes rilays V and A, Fig. 3, to operate with the result that a circuit is established from earth 15, through 4, 3, 10, 10*, wind- This Bill, RN, line wire to subscribers telephone 54, 55, 64,1elto ground, 15. Relay l) now operates, causing spring 42 to break connection with battery 14, through 43 and make connection with ground 15, through 11, 22 and 20. A current is now caused to flow 'from earth 15, Fig. 3, through '29, 212, ll, 42,

28, 27, (32, winding of relay R, 56, 57, RB, through selector and line wire RL, Fig, 2, through telephone set Fig. 1, back over line wire VL, through selector Fig. 2, through winding of relay V Fig. 3, 63, to battery 11, and earth 15. Relay V and R are thus energized. Relay A, however remains inert, owing to the fact that windings 62 and (33, under the condition described, oppose each other. By the simultaneous operation of re lays V and R a circuit is established from earth 15, through 9. winding of relay C, 14 to 15. Relayv O operates and causes spring 35 to break contact at 34 and make contact at 36. In this condition, the connector permits of conversation being carried on between the calling and called stations. Condensers 16 and 17 afford a path for the voice currents from the selector banks VB and RB to the connector wipers, VW and RV, respectively. 'At the end of conversation, the subscribers hang up, The release, however, is controlled entirely by the hanging up of the calling'subscriber. The act of hanging up or pulling down the switch hook, momentarily grounds both sides of the line simultaneously. In other words, referrin to Fig. 1, contact is made simultaneously 'etween s rin 70, 71, and 72. The result is that re ay Fig. 3, up erates, for the reason in case the called subscriber has not yet hun up, that one of its windings (S2, is shunte out by the 'ound at subscribers station, thereby nul ifying the differential action of its two windings. Should the called subscriber have hung up first, relay B again resumes its normal position, thereby connecting winding 62 of relay A to battery through 27, 28, 12 and 43. Connected in this manner the two windings of relay A do not oppose each other. From the above, it will be seen that regardless of the condition of the called line, relay A is always energized immediately upon the simultaneous grouhding of both sides of the calling line. Now consider a ain the case when the called subscriber has ailed to hang up. The ground placed on both sides of the calling line at the subscribers station, tends to shunt out relay It, at the same time it shunts out winding 62 of relay A. It is found in practice that the short circuiting of relay R as described above, results in it being made sullicicntly slow acting to permit of contact between springs 1 and 2 being maintained until after relay A has operated. The result is that a circuit is established momentarily from ground 15, through 1, 2-, 2G, 25, winding of relay D, 36, 353, battery 14 to earth 155. Relay D now operates and makes contact between springs. 30 and 31, thus placing a ground on 21, 25, and 26 and thereby sustaining both relays O and D as long as relay A remains energized. Should the called subscriber hang up first, relays V, R and A and 13 all resume their normal position for the reason that the circuit through relay B is opened at telephone of the called subscriber, thereby causing relay B to place an equal potential on both sides of the calling line, with the result that no current flows through relays V, R and A. This is accomplished by transferring spring 42 from connection with ground through spring 4-1, to connection with battery through spring 13. Incidentally it is by this means that the calling line is afforded supervision in cases where the call originates from a private exchange or other switchboard requiring supervision.

\Vhen the calling subscriber releases the connection under the conditions above described, the momentary grounding of both sides of the line causes the simultaneous operation of relays A, R and V with a result that relays C and D are energized as previously described. It should be noted, however, that winding (32 of relay A is transferred from battery connection to a ground connection by spring 27 breaking mntact with spring 28 andlnaliing contact with spring 29. Therefore, sliould the ground on the calling line remain for any appreciable length of time, winding (32 of relay A and of relay R will be shunted out. The re sult is that contact will l broken between springs 1 and 2. Both relays C and D, however, will be sustained as long as the ground remains on the line, owing to the fact that relay A is still energized by winding 63, thereby closing the circuit including the windin of relays C and D at 2st, and 26. lien the ground at the subscribers station is removed from the calling line, relays V and A resume their normal position, thus opening the circuit through relays C and D at 26, 2-5 and 2%. As previously stated, the air gap of relay 0 is adjusted so as to cause it to resume its normal position in a shorter timethan relay D. The result is that the release circuit lSJIlO mentarily closed at 34 and 35, a circuit being established from ground 15, through battery 14, 35 and 34, winding of release magnet G, 33, to private bank contact PB, of the precedin selector, Fig. 2, thence through wiper of t e selector, PW, Fig. 2, winding of release relay RR, 89, 89 to ground 15.. The closing of the circuit operates the release magnet G, Fig. -3, which in turn releases the connector shaft which reslunes its normal position and at the same Hit) Specifically described.

time kicks, so to speak all four side switches, 10, ll. 12 and 13 back into their normal or first ptsition. Due tothe low resistance, ol the release circuit, relay RR, Fig. 2 also energized, with a result that a local circuit through the selector release magnet M is closed at 93, Fig. 2. The so leetor shalt is now released and allowed to resume its normal position. At thesame time, the tire side switches, 88, 59, 90, ll and 92 are forced-latch into their first or normal position. Should additional selector. be intolu l' in the connection the method of release substantially the same. The connector and selectors are now in their normal position and the subscriber at the calling ttll'ltill may proceed to make other 'alls.

The description so far pertains to the setting up and releasing of a selector and connector on a regular connection to a nonbusy line. The special features which form the body of my invention will now be more First I will take up the noi'i-interlering feature o'f thc connector release circuit, which prevents'a premature disconnection should a seco'nd party come in on the calling line and attempt to call or in any other way ground the calling line. It will be noted that the grounding of one side of the line when the telephone set of any station is bridged across the line, is equivalent to grounding both sides of the line, the ground supplied to one side of the line being transmitted to the other side through the closed circuit of the telephone set. It is for this reason that contact springs 73 and 7-l. Fig. 1, are arranged to open whenever the calling dial is moved out of its normal position. Consider the case when the calling subscriber is waitingfor the called subscriber to answer. Under these conditions, all relays in the connector, Fig. 3, are inert, and all side switches, 10, 11, 12 and 13 are in their third position. A second party now comes in on the calling line and places a ground upon it thus operati-ug relays V, R and A, Fig. 3, a circuit being established from the ground at the subscribens station over the line wires, VL and ltl), through the windings of relay V, lt and to battery. The operation of relays V. ll and A results in simultaneous op; eration of relays C and D, a circuit being first established from ground 15, through 1 and 2, winding of C, l-l to 15. Relay C upon operating, causes another circuit to be closed from 15, through 1, 2, 26. 1-15, wind iug of l),1ltl. ilfi, l-l to l7]. ltelay l now on crates and in so doing, causes svvlnglug spring 27 to break contact at 2% and make contact at 25 The result is that winding 62 of relav itran-terred from a battery to a ground connection. llelay however, remains energized by virtue of applied to the calling line.

current l line.

flowing through Winding 63. The contact made between 30 and 31, places a ground upon armature 26, with the result that both relays C and D are sustained. The transferring of the battery connection to a ground connection at 29, causes relay R to fall back, thus breaking contact between springs 1 and 2.

'hen the ground from the interfering station is removed from the callingline, current is caused to flow from ground 15 Fig. 3, through 29, 27, G2, winding of R, 56, 57, RB to selector Fig. 2, line wire RL, through closed telephone circuit of calling station Fig. 1, back over line wire VL to selector Fig. 2, then through winding of relay V, Fig. 3, 63, battery l l'to earth, 15. The restill is that relay Ris again energized and contact made between springs 1 and As previously stated, the windings of relay A act differentially when connected to ground and battery respectively. Therefore, relay now resumes'its normal position, with a result that contact is broken between springs 2+, 25, and 26. This opens the circuit through relay D which now resumes its normal position and in so doing transfers the ground connection of winding 62 at 29, to a battery connection at 28'. In this manner, both sides of the -.calling line are again. placed atthe same potential, thus causing relays V and R to resume their normnlposition, thereby opening contact between 1 and 2 and denergizing relay C. It will be noted that' relay C on resuming its normal position does not close the releaseeircuit through release magnet, G, since the latter circuit is open at relay D. Now consider a case where the called subscriber has answered. In this case, relays V, R and C are energized. The result of grounding the calling line by an interfering station, is to cause the operation of relay A which further results in the operation of relay D and of the deencr izing of relay R, all as previously stated, he connector circuit remains in this condlt; on until after the interfering ground is removed "from the calling line, after which relays V and R again operate, and relay A resumes its normal position, also as previously described. Relay D now resumes its normal position and the condition of the connector is the same as before disturbing ground was From what has been said, it will be seen that the connector circuit is such as to make a premature disconnection impossible, and

that a disconnection an take ..place only when the calling line is opened immediately following the simultaneous grounding of both sides of the calling line. Sh uld the called line be busy, the connector will release automatically except on a reverting eall in which case the called line is also the calling When the tinal ground is placed upon line is busy, an earth connection will be 49, winding of release magnet G-34, 35, i4

attempts to ring, which he does by depress 26 switches, however, remain in their first posi- 80. The stepping up of the connector shaft out $0 place as previously described. Should the on a reverting call are in contact with connector bank contacts of the calling line, and RN. When the connector is in the position shown in Fig. i and the final ground is supplied to the rotary side of the line BL, relays R and A, Fig. 3, operate in the usual manner, causing in turn 'the operation of private magnet, PM, with the result that contact is made between springs 6 and 7, Fig. 4, causing a current to flow from ground 15, throu h 7, 6, winding of V to. bank contact V thence to wiper VW, through 12, 12B winding of F, battery 14 and again to cart 15. Relay F is now enerzed and opens the connector release cirso cuit at 60, 61, Fig. 3, permitting the connector to step into its third position. Since relay F is a ways connected to the vertical wiper VW when the side switch is in its second position, it is necessary that the cirs5 cuit be so designed as to permit'the wipers to pass over or select busy and non-busy contacts other than of the calling line, in the connector banks, withoutenergizing relay F. This is accomplished by making the windin 9f relay F of such a resistance, prefera ly high, compared with the resistance of the windings of bridged relays V, R, A and B, so that relay F will not operate' when shunted by the windings of the former relays.

In Fig. 5 is shown diagrammatically, three ossible circuit conditions of the'connector bank contacts of busy lines, met with in actual practice and in connection with which relay F, Fig. 3 must not operate.

Fig. 5", represents the line circuit operation of a set of connector bank contacts of a busy calling line before the called subscriber has answered. In this figure, V, R, 62 and 63 represent the windings of relays V, R and A,-Fig. 3. Should wiper VW, with side switch 12 in its second position, pass over bank contact VN under'the conditions shown in Fig. 5*, relay F will obviously not operate for the reason that no current flows, it being understood that'the batteries shown are of the same potential.

Fig. 5 represents the line circuit condition of a set of connector bank contacts of a busy calling line after the called subscriber has answered. Here relay B of the connector, Fig. 3, has 0 erated, substituting round for battery on t e rotary side of the calling line. Should wi erVW 1pass over line wire RL, Fig. 1 at the subscribers station, the four side switches of the connector Fig.3, are in their second position. There- -fore, when the private magnet, PM, is ener 5 gized by the operation of relays R and A, a circuit is established through relay E, from ground 15, winding of E, 9, 8, 22, 23, 14 to 1 5. Relay E operates and closes contact be- ,.tween springs 48 and 49. Since the called found on the private bank contact, PN, for reasons previously given, thereby establishing a circuit from the grounded bank'contact PN, through PW, 13, 13, 61 60, 48,

to 15. The result is that the connector releases, causing the connector shaft and the side .switches to resume their normal positions. Thus, when the calling subscriber ing ringing key, 15, Fig. 1, grounding line wire VL and causing relays and A, Fig. 3, to operate, the vertical magnet, VM is stepped up one or more levels. All side tion,'ow1ng to the fact that the ground applied'to the vertical wire VL, is not, followed y a similar ground on the rotary wire, RL, as is the case when calling with the dial.

of its normal position, causes contact to be made between springs 58 and 59, thereby transmitting the busy tone connected to 5 ring 58, to the rotary side of the line tlirough side switch 11 in its first position, The busy tone thus applied, passes through the subscribers set on the calling line and is heard by the subscriber, upon the receipt of which he hangs up, the disconnection taking call have been a reverting call, that is,should the called line have been the calling line, the operation of the connector up to the point where relay E is energized, is the same 45 as above described. However, on a reverting call, relay F is also ener ized, thereby ope'ning the release circuit etweensprlngs 60 and 61 and allowing the connector to step into its third position as on the regular con- 50 nection.

In Fig. 4 is shown diagrammatically, the circuit condition of the calling line on a reverting connection with the side switches in their second position. VL and BL repre- 55 sent the line wires to the subscribers station;

VW and RN the calling line contacts in the bank contact VN, Fig. 5 relay will not connector banks; the dotted lines represent operate, owin to the shunting efiect of the the established circuit through the interme winding of re ay V and winding 63 on relay diate 'selectors;Y,R,62 and 63 represent the F, the shunt circuit being established as 60 bridged windings of relays V, R and A; 64 followsrfrom ground 15, i

and 65 represent the bridged windings of winding 62 of relay A, winding of relay R, relay B; F represents the windin r of relay to bank contact RN, thence through the cal F. Other parts may be identifier by their in subscribers tele hone set back to verticorresponding numbers in Fig. 3. VVV and ca bank contact At this point, the

6 RW represent the connector wipers which: current divides, part going to battery 14, 130

g'. 5, through through windng of rainy V and Winding 63 of relay '1 Fig. 5" and pan ihrmigh wipm" 1V, 1" and winding of wlzay F.

, rs V and B simian. m miin u' JR :1? the Wmiml -llimn limited party line service, such as for ample is illustrated by the tour party line system shown diagrammatically in Fig. i

and previously described. Here, as before 5 stated, each ringer is designed to operate only on current from its corresponding ringing generator at the central otlice. In this sys tem there would be four groups of connectors, each group being arranged to supply a distinctive kind or arrangement of ring; ing generator current. The circuit of these connectors would be substantially as shown in Fig. 3, the dill'erence being in the nicthtjid of connecting the. ringing generator t springs 50 and 53 of the ringing relay RR and to the springs of relay B. To meet the conditions shown in Fig. 7, each group ol connectors would have the non-gro-maled pole of the source of ringing generator current connected directly to contact spring 50 Fig. 3, the grounded pole of the ringing.

generator current. lining connected to spring 53 through swinging spring 39 and relay B. In this manner the ground connection would be removed from the vertical line Wire VL on a reverting connection the ground necessary for the operation of the ringers at the subscribers stations, being supplied by the ringing key K K etc. shown in Fig. 7.

The object of condenser 47 Fig. 3 in. the connector ringing circuit shown in, Fig. 25., is as before stated, to prevent a path for di rect current during the operation of the connector on a reverting call, when the ringing key is released. When. the ringing key 1S depressed, relays V, A, B and ltll are 1 When the ringing key is reenergized. leased, the ground is removed 'lrom line wire 40 VD. allowing relays V, A and B to drop back which they do, since relay RR- controlled by relays V and A it does not drop back until later, therefore, contact is not. made between springs at] and 57, with the result that no current flows in the ailing line during the interval between the falling back of relays V, A and B and relay ltlt. Should, therefore, condenser 47 be omitted, a current would flow from ground 15, Fig. 50 3, through 46, -15, 50, 51, 11, 11 lllV, RN, over callfing line wire BL to subscribers station, through telephone set back over calling line wire VL through selector Fig. 2, to VB Fig. 3, thence through winding of relay V, winding 63 of relay A, battery let to earth 15. The result would be the locking up of relays V, A, and RR.

The object of connecting winding 65 of relay B, Fig. 3 to ground ll, through out oil contacts 21 and 22 on relay A, is to prevent chattering of relays A and B when a reverting connection is established. If the cut oil contacts referred to were not pro vided and ground 15 were permanently connected to winding 65, a circuit for a current flow would be established on reverting calls from the ground on winding hi1 through winding (i5, 52, 5t, ll, ll, l'lW, RN; through selectors back to ltil, through 57. 56, winding oi ll, winding [312 of relay A, 27, 23, 42 4.3, battery llto earth 15. The result is that both relays A and l are energitaed. The operation of relay ll, houwver,

transfers pring il-2 from connection with battery ll, through lit to a ground connection 1-). through -ll. A ground lfUiiIlCtll Il now (Hints at ea h end ol the circuit just des ribed, causing the current [low to cease with a. result that. both relays drop hurl; t their normal position, again creating the condition causing their operation. ln this nnsnncr, relays and ll will chatter indeliuitely.

lo the preceding specification. the ltllll battery as used includes any suitable sour e of constant potential direct current.

What i claim as my invention is:

l. in an automatic telephone exchange system, the combination ol 3 olling telcphone line, a called telephone line, a con nector for completing unmet-lion from the calling line to the called line. trunk lines and a plurality of trunking switches for extending the connection lroui the calling line to said conmirtor, a grounded source oft current trr em-rgixing said connector and trunking swit hes, a int-ans of grounding both sides ol milling line. a. means of relea ing the wmnection following the grounding f both sides of the calling line only when said calling line is open and clear upon removal of said ground.

In an automatic telephone exchange systei'n, the combination of a. calling tele phone line, :1. called telephone line, a connector l'or ('(lI]l}')lUllIl 2 connection from the calling line to the called line, trunk lines and a plurality of trunking switches for extending the connection from the calling line to said cliuiucctor, a grounded source oi current for ener Zing said connector and trunking switches, a means of grounding both sides of calling line, a train of relays associated with said connector, arranged to release the connection following the grounding of both sides of the calling line, only when said calling line is open and clear upon removal of said ground.

In an automatic tele )hone exchange system, the combination ot a calling telephone line, a called telephone line, a connectorfor completing the connection from the calling line to the called line, trunk lines and a plurality of trunking switches for extending the connection from the calling line to said connector, a grounded source of current for energizing said connector and trunking switches, a means of releasing the connection following the grounding of both sides of the ceiling line protidine Fill" plurality cl stations on said A called line a ronuwtor lot c niiilvtiiui a con nection from one station on said willing line to another r-lillltlll on said ("tlllllfl line and from the milling line to the called line, ll'illll( lil es and a plurality of trunlting switches for extending the rmnnrrtion from said ailing liue to said Minuet-tor. a connector ltltllr-t circuit, a m ans ol' closing said connector release ircuit on an attempted connection with said called line it busy, a plurality of calling lint: i'vl'lliliullS, a. plurality of called line terminal a plurality of Wipers Forming part of said connector artinged to engage in electrical contact said terminals ol' either the calling or *allcd lines, a relay ada dcd to ill c nnected to one of said wipers arranged to open the Philnectoirelease circuit on an attempted (U11- nection \illli 5: id calling line, thereby perntitting llu count-clot to t--l2llili li a connection with said all ng: liar, lat! not opening the connector releas til' ftlll' on an attempt,-

ed connection with said called line, thereby causing connector to release it called line is already migaged in some other connection, a source of current for energizing said connector and relay.

ll. in an autcmatiitelephone exchange 5 tom, the L'Utllllllltllltllt ot', a calling lint, a plurality of slations on said calling line. a connector for c'oniilvting a connection from one station on said ailing line to another station on said calling line. trunk lines and a plurality ol trunking switches for extend ing the connection {tom the cal ing line to said comm tor, a t 'Hiltt 'lHI rclcui-r circuit, plurality of calling line ltl'iltlllill I pin ,i it ot \Yil IPI Z. forming part 0 rid roar ncctor. arranged to engage in tlttilj'tifni con tact said terminals ot r.1llingiii|c,a roiiiul' ed Source ol' current to! operating said connector and trunking euitches, a nit-ans of releasing the colnicliition following the ,gtroundin; of both sit o he calling line. only when e id rail g line is o icn and clear upon removal of m nd, a n'axans oi auto nlaticall v opening; the connector release eir cuit on all Hilllliilitfii eonmction with the calling line, thereby permitting the connector to establish a connection with the said calling line.

In an automatic telephone exchange system, the combination of, a calling line, a plurality of stations on said calling line, a connector for completing a ciiinnectiiin from one station on said calling line to another station on said calling line, trunlr lines and a plurality of trunking switches for (X- tcnding the connection from said calling lilK' to said connector, a connector release circuit, a plurality of calling; line terminals, aiity of Wipers fornii L7 part of said arranged to engage in electrical m ling line. a l ontact said terminals of said calling line,

a grounded source o1 current for energizing said connector and trunking switches, a means of releasing the connection following the grounding ol both sides of the calling line. providingsaid calling line is open and clear upon removal of ground, out: also arranged not to release the connection, if upon removal of said ground, a closed circuit is maintained between the wires of the calling line, a means of automatically operr ing the connector release circuit on an attempted connection with the calling line, thereby pern'iitting the connector to establish a connection with said calling line.

ltl. In an automatic telephone exchange system, the combination of a calling line, a plurality of stations on said calling line, a called line. a connector for completing a connection from one station on said calling line to another station on said calling line, and from said calling line to said called line, trunk lines and a plurality of trunking switches for extending the connection from said calling line to said connector, a connector release circuit, a means oi closing said connector release circuit on an attempt;- ed connection with called line if busy, a plurality otf calling linc terminals, a plurality ol called line terminals, a plurality of wipers, forming part; of said connector, arranged to engage in electrical contact, said terminals of either the called or calling lines, a grounded source of current. for operating said connector and trunking switches. a means of releasing the connection following the grormding of both sides of the ailing line, only when said calling line is open and clear upon removal of ground, a means of automatically opening the connector release circuit on an attempted connection with the calling line hereby rinitting the connector to establish a connection with the said calling line, but not opening the connector release circuit on an attempted connection with said called line, thereby causing the connector to release if called line is already engaged in some other connection.

15. In an automatic telephone exchange system, the combination of, a calling line, a plurality of stations on said calling line, a called line, a connector for completing a connection from one station on said calling line to another station on said calling line, and

nails, a piui'uiiiy (if Wipfilfi, forming part the Cuiiuii m: cziiiing lines, :a gi'mmiiw! awful-re :1 m :11) iii ie: mm' um iliiiuwm iim grmimiiilg iii iniiih 4 ea 1;! {im ziliizig iimq pliii'iiiiii i' n'ziiii Pziiiisz' iiiw is u; '1: mil rival up?! IEEIEUC of 111mm but 1 n il'lmii}: [i JLHi hi r1" the ammunition. i ug'mla ra znmzii grriund :i win Lw n t 0 wii' s Hf Hui railing line, a means of iuitwinaiimli vpvzsiiig iiii; L'i'iiliilfifil" 1%" lease circuit on HM niii im'ueii CUIIDCTiiOD with said i'aiiiiug iil marshy permitting the cums; JiUI' In +1 zlii-iil-iii ii connection with Wining [min but nut ii wiiilig film n1 ri iczisc vii-sun mi ziifl-mpiefi WiLii i iii (fiiiiQi 7 iiici'vii itminmwi' i-Ji liikfilS, if Said 9 n5: is already engaged. in 5mm: other gunned inn.

16. In an :mwinatii: tisystem, a iIli'Ji iui; a siiiiing; Fine, a piui'aiity (If siziiicms on 1ii i Qiiiiin iine, 1i ringer at each station, arranged in ring only when siippiiisii with & g iariicuisr kind s1 fir-- iangssm :iv 0? vi v liming ii 1. mnsii c V kitiil i n-M11: iiue, a pin uiiiiy at iii. a :5 v line, a i-iligm' {if each sataiwn, arranged to ring wily when suppiiird Wiiii i=1 pafstimiiar kind 0 arrangement of ringing generator CUIIQBHL a piurality cerium/102$ cmnpiating cqnii (riwmi is maintained ueneciiun [rem any station on said caliing line in any other statiml on said caliiug line, each cunncutnr being an'angmfl to supply a partimim' kind or :nrnugument of ringing genwuinr cui'i'eni mtlw pil'iiiii ll ut' its wri'vspuuiling: ringer, iriink lines {m ni :1 pini'uiity ut' trunking swiiuhcs fur C iumiing iiiw umiimrmrn from in aliing lizm to die yimpii' iiiiillR'LiOl', (-af'h (mmlcctur having a re-imw ril'riiii, a iiui'aiity (if railing iimih-imimais, :1 1':i!.ii''2iiiff 0f wipers farming pnri uf mil-h mnncctoi' :zmi u'mngmi lo ell-- gage in eiect l coiihu-i mid iurminnh (B-f said (tailing iina grmiiuimi FHUIUJ If current {UT (qtieansmig said cunnccturs and mid trunking rm'iivhcs, +1 means of releasing ihe mnnwctinn, i'iiilmving the grminding if buijii sititrfi ,uf ihu mailing line pi'miilwl ing iim: EH upwi and Hen ilpun gi'fiillui, i m.) iii'i'zuigjmi uni in reivuszx thu cmiziwiwai pun Iilllh'wili of "aid ground, a sinned 0i ii it is inuiiiiaimid. imiwcvn the wires of i. viiiiil line a iiluuns of aimimaiii-aiiy Opening 1e cunneuim r010: iir- ULiiE Gil an attumpted cunnuciiiini with the cniiing line, thereby permitting the son" neck? in ustabhsh ii cmmechi'ii': wiiii said mgezi to ring only Whuii w'ppiiwi with it .li'uizu kind or mizingmneiit 0% ringing gmwiamr i'iii'ieiii, {L piui'aiiiy if l'iillliifktlll'S f0:- mmpiifng i wnneciinn ffrum my striiimi un, miii railing; line in an u'tiiei' m on mid miiin g iine or said caiiiid iinw, ma l; (f-Hfiii'iifli iming' arranged in suppiy a 1 mini kiwi m" ai'iaingeizieni of fin nemtm' mi-rent for the operation iwapmiiiiiag ringsr (aziiyn trunk iine 'i' imuiii (if trim :ing swithm for 0:01 ing iruimavtiuzi from the?! Jig Haw i=1 'h e pmpei' ({Iliflfllii OlZ, fifziil ammesm' ha F L 19f rziiiing iinet i] s in nuliuii iimz terminfijlillifl" .m 05 921 i. iih} (H11 2i graiundmi smirce (if consie hlrs and i1 m rvie: mg the wmziwir tiun iilfi grounding of iflitil V of ang line, only when said, mailma line is Upen and clear upon removal 0f gmund, means of automatically opening the connector release circuit on an attempted connection with the (sailing line, thereby per mittiing the connector to establish a conned tinn with the calling line, a means of cansing each connector to supply its particular kind 0 arrimgouient of ringing generator current to the calling and called lines.

19. In an automatic telephone exchange system, the cranhiinitiiiui of, a calling line, a plurality of stations on said calling line, a plurality of called lines a plurality of sta tions on each of said called lines, a ringer at each station of said called and calling lines, ar ranged to ring only when supplied with a particular kind or arrangement of ringing generator current, a plurality of connectors for completing a connect ion from any station on said calling line to any other station on said calling line or on an id called lines, each connector being arranged to sup ply a particular kind or arrangement ot ringing generator current for the operation of its corresponding ringer only, trnnl; lines, and a plurality of trunking switches [or ex tending a connection from the calling line to the proper connector, each connector having a release circuit, a set of calling line terminals, a plurality of sets of called line terminals, a plurality of wipers forming part of each connector, arranged to engage in electrical contact said terminals of either the calling or called lines, a grounded source of current for o 'icrating said connectors and trunking switches, a means of releasing the connection following the grounding of both sides of the calling line, providing saidralt ing line is open and clear upon removal of ground, hut also arranged not to release the connection it upon removal of said ground, a closed circuit is maintained. between the wires of the calling line, a means of automatically opening the connector release cir ruit on an attempted connection with the calling line, thereby permitting the connector to establish a connection with the calling line, a means oi causing each connector to supply its particular kind or arrangement of ringing generator current to the calling and called lines.

20. In an automatic telephone exchange system, the combination of, a calling line, a plurality of stationa on said calling line, a plurality of called linen a plurality of stations on each of sad called lines, a ringer at each station of said called and calling lines, arranged to ring only a J supplied with a particular kind or arrangement of ringing generator current, a pl rality of connectors for completing at noon ion from any station on said calling n9 to any other citation on a; id calling line or or s id called lines, each conntuior hen: aim god to sup- 3 ply a paitirular ltinil or arrangement of ringing generator rurrrni or the opcl'atimi of its c l 1 :ponding ril only, trunk lines and. a plurality of n uniting switches to! ex tending a connection from the calling line fnrn'iing part of each connector, arranged to engage in electrical contact said terminals of either the calling or called lines, a grounded source of current for operating said connectors and trunking switches, a means of releasing the connection following the grounding of both sides of the callin line, a

only when said calling line is open an clear upon removal of ground a means of mitomatically opening the conductor release circuit on an attempted connection with the calling line, thereby permitting the connector to establish a ct'innection with the calling line but not opening the connector release circuit on an attempted connection with it called line, thereby causing the connector to release it said called line is already engaged in some other connection, a means of causing each connector to supply its particular kind or arrangement of ringinggenerator currcnt to the calling and called lines.

21.. In an automatic telcphone excharige system, the combination of, a calling line, a plurality of stations on said calling line, a plurality of called lines a plurality of stations on each of said called lines, a ringer at each station of said called and callin lines, arranged to ring onlywhen supplie with a particular kind or arrangement of ringing generator current, a plurality of connectors for completing a connection from any station on said calling line to an other station on said calling line or on saiti called lines,eaclrconnector being arranged to supply a particular kind or arrangement of ring in g generator current, for the operation of its corresponding ringer only, trunk lines and a plurality oftrunking switches for extending a connection from the calling line to the proper connector, each connector having a release circuit, a means of closing the connector release circuit on an attempted connection with a busy called line, a set of calling line terminals a plurality of sets of called line terminals, a plurality of Wipers forming part of each connector, arranged to engage in electrical contact said terminals of either the calling or called lines, a grounded source of current for operating the connectors and trunking switches. a means of releasing the connection following the grounding of both sides of the calling line, providing said calling line is open and clear upon. removal of ground, but also arranged not to release the connection it upon removal of said ground, a closed circuit is maintained between the wires of the calling line, a. means of automatically opening the connector release circuit on an attempted connection with the Hilly];

line thereby permitting the conm::: l'::l |isl1 z: cunnecliuu with the milling lim liill ml owning: the rcmnw-lm i'Plttlfl' rim-nit (in mi nth-mpli-(l rumirrlinn Willi -i mailml line. llwm-lay muising ilir rimuurtmlU rvlrzmv if sniil L'dilOll iinv is =lliriiily PDQ-HIGH in s m Hilll'll unnnurlimi. :1, mmn if will lug mirl! minim-1m to supply ils 1111* iia'nliir mm] m :u'nmgizmrn if ringing: gruemtiir current to the milling and mlilml lines.

culling nerinr in i3 :mlmnzilii: lclqilmur, rxrlsmifl s gs:em, lli:i :viimliiinatiun (if, :1 milling h r: plurality li slniimm on will Milling 1: ringirr at fill Fainlimr :u'rnngmi in rim} unl v wiwn sup iizw in any other sratiiin {in 321211 ing line (H1511. i'rnzin utor (wing arranged in aly a partiruliir mind 0? arrangement of nt for the cpei'alimi 91 irimii lHliib and lifiilif; f0! exififi tl 111;; the :HUSF-fiifiil frum the mining line to the prn wiw urmnwlnr rash rmmecmr lmv m misuse circuit a plurality 0f (falling: lint: terminals a: plurality of wip i-rs. furmlug purl if curl: uzniiwliir, fil'iz'li' il in imga '5 in vlwu l will Hfl'flllilfllh m 11:] willing: r luy ilhlllpl'k l [1: in? win- Her-mi in mm; iii will:

' in upon swi'unml ziily liw' will? tr: lil l lllrlillf lrlrplinnr :xrl

iiiiii iinziliuii ml, :1 milling l :1 plumb. hf hlllliHllH nu Quill (filling; ii:

stzliiiiim in: will 0% said railed lineal: iii:

:14: (.Hll slnfi'in (if Sllill L'ulleril {mil will linrR, .1l"ii:* i in ring only Wlllfll mpnliu ii tl or zirrzinigrmr iilw ra ruin rrlm living :u ;c:l any pl); :1 pili i 'liirii ii m' :srrau-g v :7 ringing gi'ii 'ltii ll lll'Y'xlil for the opeaiion of it: mr-rw illing grr unly, trunk lia w ll 1: rliivsi ml irliiiliing mvilrliwi fur limin -l"l fill" ll lll i'riim ll-iirailing lilw in the [H'MIHH' l' HiI1 'i:l' i-iwli i'llil iflfile'il having :2 i'tllllH. i'il'l'llil wt if milling line l0!- minuls, :1 ilin-Mil: iil' sols: of culled line tr! urinals 2E plurality 11F wipers Forming purl of each. (wanna-slur. arramgwl to engage in HF nil ll i eleclriral (Ohititl Quill imminals (if Qiihfi! :m mil ng or milled liner: a relay adapted M ii? rfiin'ieriml 0 mm in" ill wipers of vac]; roin'mclm", arranged tn ripen tin nunnvulor release z-ircsiir m1 m1 alimnpiwi connection will! flw railing; line liri'r-iiv iiiii itling The (mum- 1w cslzsli amt-dim: with Hiiiii limz l rlirrrnh for vriri' gg 11;; irl (lailllli-lt whys and tllll1l(- ing swifrlr, and it im-uns :1! 1'=.izsing each l' ili'iiiiwl in eiiip il v in: i zrlirulilr kind 0): :iriir gvuwiil ml ringing ggczwriitnr rrurrrnt in 51ml (itlilllji will I, lllril lines.

in in. :mlnn filir tr-laplimm exchange 5y '2, tin: umnliiuatin'n f :1, pair 0f line wry a: ringer liriilgr-il EHJHISS szml lmuWlIQS Zn. in rm ammmuliu tuinplr "-m the mnnbinatimn if :i. i: r line :i ringer bridged ncru Bind line and a ringm iridium-led i'rmn U516 of 1 line WHICH to mull], a suurce 0! gruumlml ringing generator rui'simt, a in ms of supplying said grounilleii BEWJLL'G (if ringing generator current l the line Wire tonne-"(ml in the grounded ringer iliereby upvrruing llm griml'uleil ringer 1W1: wit the lirinigc l rings-r, :1 r mz ni of supplyang said wznrlril swurre (at rmgn'ig gEIiPZ'RlAH (HT- !,u this ilnv sir-1: nut iznnnerled in mud i ger and r: griiui'ul Pr i= ing limo Wire ilwr 'l L v er but film imlml ri'iigfari l fi it in wound by time line win 5:; :1 llljll it is cum mailed, :1 111921119 of applying said sourceiiof p'ri'iunilwl ringin" emzratnr mu'rent t0 the line wire w nne is the griizmderl ringer mail a ringing ltiil tGCl with 88011 ringm' m'rungr jl I nail the remainin fine wire, thereby spending either or bot ringers.

26. In sxsiiems, sailin :ine brunt.

'UHHGClOP for ielqlwne exchange a called. line branch, two speech cmrcnt onductors coir nccting said calling and said callcd linr branches, two calling liner tcrininals, tw wipers forming part at said callcd linc branch and adapted to hc cmmcrlcd nith said spccch cnrrcnt conductor; a mimcrtor rclcafsc circuit, a gronni'lwl Wllll'l'lj of rurrnnt for opt-rating said cm'incct r, a Illtzlllr oi air plying a ground to onc 01' said \riprrs. a irlay adapted to l)( ronnwlcll to thc rcmaining Wiper and arrangml to urn-n raid councillor rclcasc circuit whim and ground i amiliwl and \rlicn said \vipcrs arc in ulm'trlial runtact with said calling linv tcrminalv. Sill? stantially as shown and tlrsrrihcll T. in a contractor for fllt'l lll lll cxclirmgc QValLlllH :1 calling lintliran h, :1 llllltll llilt j ln'anrln two hpct-cli tEilit-lll romlntrtorr coir ne ting mid calling and said calicil linc branches, two calling linc terminals, two t'illtll linc terminals, two \Vlllllh forming part (if Said c: llcd linc branch and tltltlplt l to ho cunncctvd with said spccch (lirrcnt conductorm a connector release circuit, a lncans of closing said conncctor rclcasc circuit on an attempted connection with mid calling linc tcrminals if has] a groundt'rtl source of currcnt for operating said con ncctor, a means of applying a ground to onv of said Wipcrs, a relay atli ptctl to bc con ncctcd to thc I'Olflaining \Vll t'i' and arranged to open Raid connector rclcaw circuit wllcn said ground is applied and whcn said wipcra are in electrical contact with said calling line, terminals, but also arragell not to open said connector rcleac circuit when said wlpcrs are in clcctrlcal contact with said called lino lcriuinals, thereby causing said connector to rclcme it aaitl t'allcd lino tcr lninals are already ciigagrcd in Ftllllt uthcr connection, substantially as ahown and dc scribed 28. In a telephone cxchangc system, thc combination of, a calling lclcphonc line. it called telephone linta a plurality of calling line tcrniinals, a plurality ol called line tu minals. a connector coinplt-lir :onnection betwccn the calling and callcll tclcphonc linemand con'iprising a plurality of hriilgcd relays arrangcd to supply cnrrcnt for siicrch transmission to tho ruling and allcd telephone lines, a second rm-iiwtor with a nil: rality of wipcrs illl'tlllf l t engage raid calling and callcd linc Uflllllllfllh, cat-l1 co11- ncctor having il lt'.lt'lbtf (in-nit. a inc-Lina of closing said rclcasc circuit ml the second connector Whcn Haiti connector :ill'rlnpts munection \lllll said called or calling linc tcr IlilIlfllSt rcla y when cncrgim l r nning the release circuit of said canal romwcior, lint so arrangcd an to rt %l\ inmllicivnt currcnt to he energized wl H11 the wipcrs oi said sci-and connector arc in ontact with said called or calling Linc tcrminala cngaged and in an: aut matic lclcplmnc cxcliange r l i llll. llll' l llll iiliillli ll (it a alling linc, a plurality ol' wall w n will walling line, a. wnnwlhr lul :lliirlhllill' a c- -niicrtiiin from on:- dathm on will iqillllrtl' llllt' lo anollicr fiat iwi on "lllll mil ing l no. lrnnl; lincs and illlj ll lrllnltim; \\'lll"ltl-l l t)! 0X- thw comm -lion l'ruin miltl calling i'l lllllltlill'. a llllll'l'llil 'sJQlOiLSE lnriilil ul' railing lil lf tclzninals, ol' iipcrs forming part oi said wnmw my :l lr llifwl l llga gjc in tltLlllL'tll l'tliilail mid [*lllllllillfi l' said calling line, a nit-am \llilllll ilic "llllllllltll' arranged to tllflll aaitonialirally llac ("HlZllW'lut rclcase t'll' ltll cn an atlclnptul coimwtion with the mill: lint: th i-rcliy wrnlitlingg' llic con nu tor to mtalsliah conncction with said calling: line.

10. in an aiitmnatic telephone cxchangc rm, tlw coinliination of a calling line, a plurality til? wlajiom on said milling line, a calla l line. a. rnn rtor for completing a minim-lion l'roni mic station on said calling linc t annlhrr hl'tlii l l on r-ittitl calling lin and from tl'w calling linc to thc czillcd line, trunk lincs and a plurality of trunking hdllllllH l'cr cx'icnding tlic counttion from mid calling linc in said mnncrtur. a connm-tm' ItfllitHt circuit. a plurality of calling linc ltfllllll'ltllh, a plurality of rallcd line terminals, a plurality at wipcra forming part oi Hillll lt lllltfllill' arranged to engage in clcctrical contact mid ltl'illifltllS of either tin calling or callcd liinm a moans Within tlu' comm-tic; arrancjcil to opcn the conncctor rclca r: irruil on an altcmptcd conncrlion ill: lllt calling: linc. tlicrcby permilling thc mnnwlnr tn t-Aaliiirh a con Emil-m will: will railing linci llw llL an automatic I lrphonc exchange Slum llw llllll1ll|'tllt?!l all a calling line, a

'aiily ol' aaliwiw on L id calling line, a lint, a comm-tor for completing a twin oar wtalion will calling w n il in: line mm litl alling lli {:(l line, nlulim, a? cranking 1c mnnvcth'in from filltfi l'i'flt, a conrncan of closing I on an at called line if linc termitcrzninals, a

em k

all

l i .lllli .ll

l swilcnic for cxtcmlingg; l

llllilgl lll i' in I u tor rci conncclur r.

said

in clcctrical the calling 

